nstimer安全使用block方式

NSTimer为了保证参数的生命周期，NSTimer会对target对象retain一次强引用。这样即便target销毁了，定时器还能正常调用timeEvent。因为定时器要加到RunLoop中，所以RunLoop强引用着NSTimer，一般情况下你的target就是当前的控制器，如果你想让控制器如你所愿的销毁了，首先得销毁NSTimer。不然NSTimer强引用着self，self就无法销毁，从而导致内存泄漏。
GCDTimer

#import <Foundation/Foundation.h>

@interface JX_GCDTimerManager : NSObject

+ (JX_GCDTimerManager *)sharedInstance;

/**
 启动一个timer，默认精度为0.01秒。
 
 @param timerName       timer的名称，作为唯一标识。
 @param interval        执行的时间间隔。
 @param queue           timer将被放入的队列，也就是最终action执行的队列。传入nil将自动放到一个子线程队列中。
 @param repeats         timer是否循环调用。
 @param fireInstantly   timer的第一次执行是否立刻触发，否则会等待interval的时长才会第一次执行。
 @param action          时间间隔到点时执行的block。
 */
- (void)scheduledDispatchTimerWithName:(NSString *)timerName
                          timeInterval:(double)interval
                                 queue:(dispatch_queue_t)queue
                               repeats:(BOOL)repeats
                         fireInstantly:(BOOL)fireInstantly
                                action:(dispatch_block_t)dispatchBlock;

/**
 撤销某个timer。
 
 @param timerName timer的名称，作为唯一标识。
 */
- (void)cancelTimerWithName:(NSString *)timerName;


/**
 *  是否存在某个名称标识的timer。
 *
 *  @param timerName timer的唯一名称标识。
 *  @param 查询结束回调。doExist==YES表示存在，反之。
 */
- (void)checkExistTimer:(NSString *)timerName
             completion:(void (^)(BOOL doExist))completion;

@end

#import "JX_GCDTimerManager.h"

@interface JX_GCDTimerManager()
@property (nonatomic, strong) NSMutableDictionary *timerContainer;
@property (nonatomic, strong) dispatch_queue_t queue;
@end

@implementation JX_GCDTimerManager

#pragma mark - Public Method

+ (JX_GCDTimerManager *)sharedInstance {
    static JX_GCDTimerManager *_gcdTimerManager = nil;
    static dispatch_once_t onceToken;
    
    dispatch_once(&onceToken,^{
        _gcdTimerManager = [[JX_GCDTimerManager alloc] init];
    });
    
    return _gcdTimerManager;
}

- (instancetype)init {
    self = [super init];
    if (self) {
        dispatch_queue_attr_t attr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_CONCURRENT, QOS_CLASS_USER_INITIATED, 0);
        dispatch_queue_t queue = dispatch_queue_create("com.JX_GCDTimerManager.queue", attr);
        _queue = queue;
        _timerContainer = [NSMutableDictionary new];
    }
    return self;
}

- (void)scheduledDispatchTimerWithName:(NSString *)timerName
                          timeInterval:(double)interval
                                 queue:(dispatch_queue_t)queue
                               repeats:(BOOL)repeats
                         fireInstantly:(BOOL)fireInstantly
                                action:(dispatch_block_t)dispatchBlock {
    if (!timerName || timerName.length == 0 || !dispatchBlock) return;
    
    if (nil == queue)
        queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    
    dispatch_barrier_async(self.queue, ^{
        dispatch_source_t timer = [self.timerContainer objectForKey:timerName];
        if (!timer) {
            timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
            [self.timerContainer setObject:timer forKey:timerName];
            dispatch_resume(timer);
        }
        
        if (repeats && fireInstantly) {
            dispatch_async(queue, dispatchBlock);
        }
        
        dispatch_source_set_timer(timer, dispatch_time(DISPATCH_TIME_NOW, interval * NSEC_PER_SEC), interval * NSEC_PER_SEC, 0.01 * NSEC_PER_SEC);
        dispatch_source_set_event_handler(timer, ^{
            if (!repeats) {
                [self.timerContainer removeObjectForKey:timerName];
                dispatch_source_cancel(timer);
            }
            
            dispatchBlock();
        });
    });
}

- (void)cancelTimerWithName:(NSString *)timerName {
    dispatch_barrier_async(self.queue, ^{
        dispatch_source_t timer = [self.timerContainer objectForKey:timerName];
        
        if (!timer) {
            return;
        }
        
        [self.timerContainer removeObjectForKey:timerName];
        dispatch_source_cancel(timer);
    });
}

- (void)checkExistTimer:(NSString *)timerName completion:(void (^)(BOOL))completion {
    dispatch_async(self.queue, ^{
        if ([self.timerContainer objectForKey:timerName]) {
            completion(YES);
        } else {
            completion(NO);
        }
    });
}

#import <Foundation/Foundation.h>

@interface NSTimer (Secure)
/// 默认 repeats
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget selector:(SEL _Nonnull)aSelector;
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget selector:(SEL _Nonnull)aSelector repeats:(BOOL)yesOrNo;

/// 默认 repeats
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget block:(void (^_Nonnull)(void))block;
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget repeats:(BOOL)yesOrNo block:(void (^_Nonnull)(void))block;
@end

#import "NSTimer+Secure.h"

@interface SeTimerTarget: NSObject
@property (nonatomic, weak) id target;
@property (nonatomic, assign) SEL selector;
@property (nonatomic, weak) NSTimer *timer;

@property (nonatomic, copy) void(^block)(void);
@end

@implementation SeTimerTarget
- (void)seTimerTargetAction:(NSTimer *)timer {
    if (self.target) {
        IMP imp = [self.target methodForSelector:self.selector];
        void (*func)(id, SEL, NSTimer*) = (void *)imp;
        func(self.target, self.selector, timer);
    }
    else {
        [self.timer invalidate];
        self.timer = nil;
    }
}

- (void)seTimerBlockAction:(NSTimer *)timer {
    if (self.target && self.block) {
        self.block();
    }
    else {
        [self.timer invalidate];
        self.timer = nil;
    }
}

- (void)dealloc {
    NSLog(@"==== timer dealloc ====");
}
@end

@implementation NSTimer (Secure)

+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector {
    return [self seScheduledTimerWithTimeInterval:ti target:aTarget selector:aSelector repeats:YES];
}

+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector repeats:(BOOL)yesOrNo {
    SeTimerTarget *timerTarget = [[SeTimerTarget alloc] init];
    NSTimer *timer = [NSTimer timerWithTimeInterval:ti target:timerTarget selector:@selector(seTimerTargetAction:) userInfo:nil repeats:yesOrNo];
    timerTarget.target = aTarget;
    timerTarget.selector = aSelector;
    timerTarget.timer = timer;
    
    [[NSRunLoop mainRunLoop] addTimer:timerTarget.timer forMode:NSRunLoopCommonModes];
    return timerTarget.timer;
}

+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget block:(void (^)(void))block {
    return [self seScheduledTimerWithTimeInterval:ti target:aTarget repeats:YES block:block];
}

+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget repeats:(BOOL)yesOrNo block:(void (^)(void))block {
    SeTimerTarget *timerTarget = [[SeTimerTarget alloc] init];
    timerTarget.block = block;
    timerTarget.target = aTarget;
    NSTimer *timer = [NSTimer timerWithTimeInterval:ti target:timerTarget selector:@selector(seTimerBlockAction:) userInfo:nil repeats:yesOrNo];
    timerTarget.timer = timer;
    
    [[NSRunLoop mainRunLoop] addTimer:timerTarget.timer forMode:NSRunLoopCommonModes];
    return timerTarget.timer;
}
@end

下面代码作者是winter找不到GitHub上的链接
这是我错误瞎使用来着 先记录下来